如何设置 UIBarButtonItem alpha

   let searchBtn = UIBarButtonItem(image: UIImage(named: "ic_search"), style: .plain, target: self, action: #selector(self.searchButton))
    let moreBtn = UIBarButtonItem(image: UIImage(named: "ic_more"), style: .plain, target: self, action: #selector(self.moreButton))
    self.navigationItem.rightBarButtonItems = [moreBtn, searchBtn]
moreBtn.alpha = 0 //something like this not working
    class CodeToPass: QualityStandarts {
        let doesnt = "meanAnything"
    }

我有两个 UIBarButtonItem。哪个是手工制作的。当我点击其中一个时，我想为 alpha 制作动画。我该怎么做？

moreBtn.tintColor = UIColor.red.withAlphaComponent(0.2)

但首先确保您的图像“ic_more”在属性检查器中呈现为默认值， 转到 Assets.xcassets，选择您的图像，然后从属性检查器中 - 在“渲染为”下选择“默认”

请注意，如果你想让它不可见，请将 0.2 更改为 0